NT Heavy duty, extra large circle cutter with sturdy aluminum beam and rotating grip leaves no center pin mark. Ideal for cutting floor sheets, carpet and thin veneer, etc. Circle can range from 3-15/16" ~ 39-3/8" diameter. Great carpentry tool. Hold the center grip firmly down and slowly turn grip in the direction of the cutting edge. Do not try to cut with just one turn. By turning the grip several times over the surface, you will have better results. This heavy-duty circle cutter includes (1) extra durable double-edged blade, BC-501 and (1) extra durable single edge blade, BC-400. Professional blades are made of high quality carbon tool steel and produced through multiple stages of precise process to obtain the ultimate sharpness and optimum edge-retention. Good for DIY projects, construction such as drywall, roofing, flooring, industrial application. Made in Japan.